A. Field of the Invention
The present invention includes a device for monitoring and wirelessly transmitting a physiological pressure. The device includes a pressure transducer and a transmitter which is in operative communication with the transducer. The transmitter is adapted to broadcast a signal which is modulated by a transduced pressure. The transmitter is also adapted to limit the power of the signal so that the signal attenuates to a negligible value within a predetermined distance from the transmitter. Optionally, the invention may also include a receiver which receives a signal broadcast by the transmitter.
B. Problems in the Art
Physiological pressure transducers are known in the art. For example, both stethoscopes and sphygmomanometers are known. Conventional transducers are utilized by applying the transducer to the patient and contemporaneously listening to the output or reading the output from a display.
Even though pressure transducers are known, there are not any known devices which function together with a transducer to make long term recordings of a transduced pressure, such as heart or lung sounds (pressure waves). It would be desirable to make long term recordings of physiological pressures for a number of different reasons.
First, recordings of sounds/pressures allows for more accurate diagnoses and for the greater use of second opinions. In conventional practice, a doctor will apply a stethoscope to a patient and arrive at a conclusion based on the sounds perceived by the doctor. To receive a second opinion, many times another doctor will be able to apply a stethoscope and hear the same sounds. However, for those sounds which are not repetitive, a second doctor must rely on the first doctor to verbally describe the sound perceived by the first doctor. If the second doctor were able to observe a recording of the sound perceived by the first doctor, a better second opinion could be utilized.
In addition, it is desirable to make long term recordings of physiological sounds and pressures to limit medical malpractice liability. For example, it would be easier for a doctor to prove he complied with the standard of care required for the situation by explaining how the doctor made a decision in light of the sound that was actually heard by the doctor. Rather than having to rely on the doctor's oral representation as to what sound was perceived, a fact finder would have the actual sound in front of it, making for a more reliable truth seeking process. There is a need in the art for a method which allows for long term recordings of physiological pressures.
One possible method of making long term measurements of physiological pressures is to connect a pressure transducer to a display or recording device through wire connections. However, wire connections can create additional hazards. For example, wire connections could lead to the possibility of the transducer being disconnected from the recording device by someone tripping over the connection. In addition, wire connections create additional problems when a patient must be moved quickly from one part of the hospital to another. Either the pressure sensor must be removed from the patient, taking additional time, or the monitor or recording device must be moved along with the patient, also requiring additional time and hospital personnel to move the recording device.
One method of dealing with the problems caused by wire connections is to utilize wireless communications between the stethoscope or other transducer and the display device. However, as wireless devices proliferate, there is an increasing probability that an output from a first device will cause electromagnetic interference with a second device. In those hospital rooms that house multiple patients, there is an even greater likelihood that wireless devices will cause interference. This is of particular concern when the devices that are interfered with control some vital function of a patient, such as a ventilator.
A wireless stethoscope is known in the art. However, none of the known stethoscopes limit electromagnetic interference by limiting the power of an output signal. Prior art wireless stethoscope utilize high power output signals which increases the probability of electromagnetic interference between devices that are in close proximity. In addition to causing potential interference, the use of a high power output signal exposes a patient to higher intensity electromagnetic fields. Exposure to electromagnetic fields has been linked with possible long term health problems. Also, the use of a high power output signal leads to quicker battery discharge when batteries are used to power the wireless stethoscopes. Finally, the use of higher power output signals increase multipath problems.
Therefore, it is a primary objective of the present invention to provide a wireless physiological pressure sensor with a transmitter and receiver having the capability of short range radio frequency transmissions which solves problems and deficiencies in the art.
It is a further object of the present invention to provide a physiological pressure sensing method and device which can communicate a sensed pressure through the use of radio frequency communication.
It is a further object of the present invention to provide a wireless pressure transducer and transmitter which minimizes the possibility of electromagnetic interference.
Yet another object of the present invention is to provide a method and device which minimizes a patient's exposure to electromagnetic fields.
It is a further object of the present invention to provide a device and method which minimize battery drain.
It is a further object of the present invention to provide a device and method which minimizes multipath errors.
These, as well as other objects and features of the present invention, will be apparent from the following detailed description and claims in conjunction with the accompanying drawings.